Safety-stop for elevators



(No Model.) P. P. CANPIELD.

SAFETY STOP POR BLEVATORS.

,ge n P M Patented July l0, 188:3.

`or of the right-hand or lett-hand well-post,

to the car.

' UNITED STATES PATENT OEEieEf.

FELIX r. GANEIELD, or noSToN, MASSACHUSETTS.

SAFETY-ST0 P FDR ELEvATo Rs.

SPECIFICATION forming part of Letters Patent No. 281,016, dated July 10, lese.

Application tiled December 4, 1882. (No model.)

To all whom ib may concern:

`Be it known that I, FELIX P. CANEIELD, of the city of Boston, in the county of Suffolk and State of Massachusetts, have invented a new and useful Improvement in Safety-Stops for Elevators, of which the following is a clear, full, and exact description, reference being had to the accompanying drawings, making a part of this specification.

In Speaking of the right-hand side or lefthand side of the elevator-well or elevator-car,

guide-rail, or guide-box in the following description, the observeris supposed to stand in front of the well, facing the entrance to it and Figure 1 is a front elevation, partly in section, of the essential parts of a platform-car elevator to which my invention is applied, giving a front view of the well-posts A A and of my safety guide-rails B B, and a sectional view of the car D and of my Safety guideboXes E E, one on each side of the car. Fig. 2 shows in perspective a section of the righthand well-post A and of the right-hand safe# ty guide-rail B, bolted to the inside of wellpost A, the forward part of the right-hand safety guide-box E bolted to L, which is a part in perspective of the right-hand side of an elevator-car, and also, in perspective, chainber F, formed on the outer face ofthe said forward part of safety guide-box E, the said chamber having teeth or notches G in its npper side, and pinion K placed in said chamber F, its teeth engaging the teeth C, formed on the front edge of safety guide-rail B. Fig. 3 is the same as Fig. 2, except that in Fig. 2

- the pinion K is shown in its ordinary position,

standing on the lower side of chamber F, its teeth not reaching the teeth or notches G, while in Fig. 3 the said pinion K is shown sus pended above the lower side of chamber F, with its teeth interloeked with teeth or notches G, as well as with teeth G. Fig. 4 is a plan vis shown chamber F, in which pinion K is placed. Guide-channel H is formed in and @across safety guide-box E to a depth about ,equal to the thickness ot' Safety guide-rail B, Zand wide enough to receive the said guide-rail ftogether with the guide-plate vI and the cushion J. The extremities of the upper and lower sides of chamber F terminate in plain faces inl the same vertical line, and constitute the forward guides provided in the safety guideboX E.

It is obvious that, as the car moves up and down in the ordinary use of it, pinion K will rotate in chamber F, the car being free to ymove in either direction so long as the teeth of pinion K do not encounter the teeth or notches G; but if the hoisting-rope breaks the car starts downward, and although pinion JK'would fall as fast as the car, if as free to `fall, andwould keep its place on the lower isi de of chamber F, yet its teeth being engagedv Ewith teeth C, it is forced to rotate as it descends, and in doing so to overcome by its own weight more or less friction between the two sets of teeth involved inthe operation, and being also partlysupported by teeth C, its descent is so far impeded that the lower side of chamber F, which moves with the car, instantly' drops L way from it, causing the teeth or notches G, in the upper side of chamber F, to encounter the teeth of pinion K and prevent its rotating, and of course arresting its descent and the descent of the car, because the pinion can fall only by rotating, and chamber F, in which it is held, is formed on the face of the safety guide-box E, which is rnily attached to the ear. The heavier the car and its load the more firmly is pinion K held in the position above described, and the more securely is the car held where it is stopped in its descent, and it can only be released by hoisting it a part of an inch to disengage the teeth of pinion K 'from the teeth or notches G, when the pinion, by its own weight, instantly rolls into its ordinary position on the lower side of chamber F, and the oar is free to move up or down until another accident occurs.

My device, unlike nearly all others in the same line of invention, provides against damage or danger in connection with the other class of elevator accidents in which the hoisting-rope does not break, but rapidly unwinds IOO from the hoisting-drum, occasioning a descent of the car at a dangerous speed. In such case pinionK will fall with the car up to a certain speed, which exceeds the speed at which elevator-cars commonly descend, but falls short of a speed that will occasion damage. With such a speed as the car is liable to attain in the class of accidents last above named, especially if heavily loaded, it falls faster thanv pinion K can fall, when the teeth of the said pinion become interlocked with the teeth or notches G, and the car is stopped inthe manner before described.

The use of cushion J, Fig. 4, is to lessen the effect of the concussion between safety guiderail B and pinion Kwhen the car is suddenly stopped in its descent, in case of an accident, as before described. It is believed that in ordinary cases one safety guide-box on each of the two lateral sides of the elevator-car will be sufficient to accomplish the special object of my invention; but two or more on a side may be employed, if deemed necessary; but if two or more on a side are employed, the con1- mon guide-boxes M M, Fig. 1, may be dispensed with.

Pinion K must be secured in its position in chamber F by suitable means, as a metal bar fastened across the chamber from side to side or otherwise.

My invention is adapted to be used as a safety-stop in connection with various bodies moving in vertical lines, as doors and gates which are opened and closed by being raised and lowered,\veights of turretclocks,window sashes, Svc. It may also be employed as a safetystop in connection with bodies moving on inclined planes.

1. Pinion K," looselyemounted in chamber F of the safety guide-box E attached to the car of an elevator, its lateral teeth on one side engaging teeth C of safety guide-rail B, and adaptedto have its uppermost teeth interlockedwith teeth or notches G whenever the speed of the car in descending exceeds the speed at which pinion K can fall by its own weight, all substantially'as described, andfor the purpose specified.

2. In combination with the car of an elevator, safety guide-box E, on which is formed cham ber F, pinion K, and safety-guide rail B, connected .and operating substantially as described, and for the purpose specified.

3. In combination with thecar of an elevator, safety guide-box E, on which is formed chamber F and guide-chamber H, pinion K, guiderail B, `and guide-plate I, connected and operating substantially as v described, and `for the purposes set forth.

4. In combination, safety guide-box E,pro vided with chamber F and guide-channel-H, and attached to the car of an elevator, safety guide-rail B, vguide-plate I, cushion J, and pinion K, all'arranged,`connected, and operating substantially -as described.

5. In combination, safety guide-rail B, safety guide-box E, provided with chamber F, and pinion K, connected and operating substan-` tially as described.

FELIX P. CANFIELD.

Witnesses:

W. M. PARKER, E. A. PrInLrs.` 

